The present invention relates to disposable dental floss holders commonly called dental flossers, and more particularly to injection molded dental flossers which each include a handle and a head part with two spaced-apart arms supporting a strand of dental floss.
In more recent years dental flossers have become widely used for removing plaque from tooth surfaces, particularly from the generally facing surfaces of adjacent teeth and for removing food particles from the interstices between adjacent teeth. Such interstices may be empty space or may be merely the interface areas of contact between the surfaces of adjacent teeth. For many persons a dental flosser is substantially easier to use than a conventional strand of dental floss wrapped about fingers of both hands and manipulated between teeth, by having fingers of one hand in the mouth and fingers of the other hand outside the mouth.
Examples of prior art dental flossers are disclosed in U.S. Pat. No. 5,538,023 to Oczkowski et al.; U.S. Pat. Nos. 5,829,458, and 4,006,750 to Chodorow; U.S. Pat. No. 7,204,257 to Crossman; U.S. Pat. No. 7,487,785 to Dougan et al. and U.S. Application No. 2008/0149134 to Crossman.
Typically, prior art dental flossers fail in two ways. First, the floss may pull through one or both arms of the flosser when a sufficiently large force is required to either insert or withdraw the floss between teeth. Second, the floss may break in response to a sufficiently large force. The first failure mode is more common and has been identified as a problem with prior art flossers.
Some designs have attempted to address the failure mode of the floss pulling through the flosser arm. One example is “knotting” the floss after it is molded into the arm of the flosser. Knotting the floss involves (1) trimming the excess floss from the area outside of the flosser arms and (2) applying heat to each trimmed end to create a ball (called a “knot”). The knots on the outside of each flosser arm increase the force required to pull the floss through the arms, but also add steps to the manufacturing process.